Virtual location aware content using presence information data formation with location object (PIDF-LO)

ABSTRACT

The format of the Presence Information Data Format-Location Object (PIDF-LO) as defined by the Internet Engineering Task Force (IETF) is extended or modified to accommodate, within the standard PIDF-LO format, an association of geospacial location to virtual content on the Internet. A filename of virtual content is associated with geospatial location information (either a specific location, zone, or direction). The filename is inserted into a &lt;presence . . . &gt; section of a Presence Information Data Format-Location Object (PIDF-LO) compliant document as defined by the Internet Engineering Task Force (IETF). In this way, geospacial location information is associated with Internet based virtual content using a standard PIDF-LO format.

The present application is a continuation of U.S. patent applicationSer. No.12/805,696, entitiled “Geospacial Location Associated withContent on a Network ”, to Donald Le Roy Mitchell, Jr., filed on Aug.16, 2010; which in turn is a continuation of U.S. patent applicationSer. No. 11/651,051, entitled “Apparatus and Method for Associating aGeospacial Location to Content on a Network”, to Donald Le Roy Mitchell,Jr., filed on Jan. 9, 2007, now U.S. Patent No. 7,805,483; which in turnclaims priority from U.S. Provisional Application No. 60/766,289,entitled “Virtual Location Aware Content”, to Donald Le Roy Mitchell,Jr., filed Jan. 9, 2006, the entirety of all three of which areexpressly incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to wireless and long distance carriers,Internet Service Providers (ISPs), and information content deliveryservices/providers and long distance carriers. More particularly, itrelates to location services for the wireless industry.

2. Background of Related Art

Location information regarding subscribers is becoming increasinglyavailable in a wireless network. Location information relates toabsolute coordinates of a wireless device.

FIG. 7 shows a conventional LoCation Services (LCS) request.

In particular, as shown in FIG. 7, a location server 106 requestslocation information regarding a particular mobile subscriber (MS) froma core network node, e.g., from a Mobile Switch Center (MSC) 110.Requested information regarding a particular wireless device (MS) mayinclude, e.g., attach, detach, and location area update. The locationserver 106 may also request information regarding the wireless devicesuch as attach, detach and/or location area update from a Packet DataNode (e.g., SGSN, GGSN, or PDSN), or help the device calculate x/ydirection. Typically, location information regarding a particularwireless device is requested of a home location register (HLR).

As shown in step 1 of FIG. 7, a locations services client 104 sends amessage to a location server 106.

In step 2, the location server 106 sends a Provide Subscriber Infomessage to a Home Location Register 108, requesting subscriberinformation regarding a particular subscriber.

In step 3, the carrier's Home Location Register (HLR) 108 provides thesubscriber information for the requested subscriber back to the locationserver 106.

In step 4, location information regarding the requested subscriber isrequested to either an MSC or Packet Data node 110. The MSC or PacketData Node preferably provides precise location information using, e.g.,a global positioning satellite (GPS), triangulation techniques, or otherrelevant locating technology, or helps the device calculate X/Ydirection.

In step 5, the location request is forwarded to the Radio Access Network(RAN) 112 if needed.

In step 6, precise, updated location information regarding the requestedsubscriber is sent to the location server (LS) 106.

In step 7, an ultimate response to the original location request is sentto the LCS client 104 that initially requested the location information.

Secure User Plane for Location (SUPL) is a standards-based protocol thathas been developed to allow a mobile handset client to communicate witha location server, e.g., as shown in step 1 of FIG. 7. The SUPLspecification is defined by the Open Mobile Alliance (OMA) standardsworking group. Refer to OMA Secure User Plane Location Architecturedocument, OMA-AD-SUPL-V1_(—)0-20060127-C for more details on OMA SUPLcall flows; and OMA User Plane Location Protocol document,OMA-TS-ULP-V1_(—)0-20060127-C. The OMA SUPL Version 1 specifies twobasic types call flows: (1) a SUPL network initiated (NI) call flow, and(2) a SUPL set initiated (SI) call flow. According to the SUPL standard,a session ID has a unique value consisting of server and handsetportions.

The conventional Presence Information Data Format-Location Object(PIDF-LO) was developed by the GEOPRIV working group, and is theInternet Engineering Task Force (IETF) recommended way to encodelocation information. Location information in PIDF-LO format may beimplemented in a variety of ways, including in presence based systems,and in the context of emergency services and other location basedrouting applications.

The PIDF-LO format provides for an unbounded number of tuples. (A“tuple” generally relates to a group of anonymous data values travelingtogether. The word is a generalization of the sequence: couple, triple,quadruple, quintuple, sextuple, etc.)

The geopriv element resides inside the status component of a tuple,hence a single PIDF document may contain an arbitrary number of locationobjects, some or all of which may be contradictory or complementary. Theactual location information is contained inside a <location-info>element, and there may be one or more actual locations described insidethe <location-info> element.

Generally speaking, the structure of a PIDF-LO can be depicted asfollows:

PIDF-LO document entity (person) tuple 1     status         geopriv            location-info         civicAddress             locationtuple 2 tuple 3

The conventional PIDF-LO format provides information relating tolocation, time and status to individuals and entities. The PIDF-LOstructure is intended for use with standardized Internet protocols,including Internet protocol (IP), Session Initiation Protocol (SIP), andSimple Object Access Protocol (SOAP).

For multi-media communications using Session Initiation Protocol (SIP),the location of a caller can be indicated in PIDF-LO format. SIP is anInternet Engineering Task Force (IETF) standard protocol for initiatingan interactive user session that involves multimedia elements such asvideo, voice, chat, gaming, virtual reality, etc. SIP is specified inIETF Request for Comments (RFC) 3261 (replacing 2543). Like HTTP orSMTP, SIP works in the application layer of the open systemsinterconnection (OSI) communications model. SIP can also be used toinvite participants to sessions that do not necessarily involve theinitiator. Because SIP supports name mapping and redirection services,it makes it possible for users to initiate and receive communicationsand services from any location, and for networks to identify the userswherever they are. SIP is a request-response protocol dealing withrequests from clients and responses from servers. Participants areidentified by SIP universal resource locators (URLs). Requests can besent through any transport protocol, such as UDP, SCTP, or TCP. SIPdetermines the end system to be used for the session, the communicationmedia and media partners, and the called party's desire to engage in thecommunication. Once these are assured, SIP establishes call parametersat either end of the communication, and handles call transfer andtermination.

FIG. 8 shows a conventional Presence Information Data Format-LocationObject (PDIF-LO) format document, as defined by the Internet EngineeringTask Force (IETF).

In particular, FIG. 8 shows an example of civic and geospatial locationinformation use in conventional PIDF-LO format document. In the givenexample, an entity named Mike is visiting his Seattle office andconnects his laptop into an Ethernet port in a spare cube. In this casethe location is a geodetic location, with the altitude represented as abuilding floor number. The main location of user is inside the rectanglebounded by the geodetic coordinates specified. Further that the user ison the second floor of the building located at these coordinates.

Of particular note in FIG. 8 is that the entity list is conventionallyused to identify a physical entity:entity=“pres:mike@seattle.example.com”Generally speaking, conventional PIDF-LO presence lists are used toidentify a person. An example person entity=Don@telecomsys.com and acorresponding example name=is “Don Mitchell”.

SUMMARY OF THE INVENTION

A method and apparatus for tying a geospacial location to virtualcontent on a network comprises identifying a filename to be tagged withgeospacial location information. The filename of the virtual content isinserted into a <presence . . . > section of a Presence Information DataFormat-Location Object (PIDF-LO) compliant document as defined by theInternet Engineering Task Force (IETF). Geospacial location informationis thus associated with virtual content.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the present invention will become apparent tothose skilled in the art from the following description with referenceto the drawings, in which:

FIG. 1 shows relevant elements associating MIME type content on theInternet to a geographic location while also correlating otherdescriptive indexing terms within a modified standards based ExtensibleMarkup Language (XML) based PIDF-LO structure as defined by the InternetEngineering Task Force (IETF), for use with standardized Internetprotocols such as IP, SIP and SOAP, in accordance with one embodiment.

FIGS. 2 and 3 show message flow between the relevant elementsassociating MIME type content on the Internet to a geographic location,as shown in FIG. 1.

FIG. 4 shows exemplary presence lists for a Modified PresenceInformation Data Format-Location Object (Modified PIDF-LO) document foruse in tying MIME type logical content to a geospacial location, and fortagging the content with descriptive information relating to thecontent, in accordance with another embodiment.

FIG. 5 shows exemplary presence lists for a location awarecontent-Modified Presence Information Data Format-Location Object(Modified PIDF-LO) for use in tying MIME type logical content to ageospacial location, and for tagging the content with descriptiveinformation relating to the content, in accordance with yet anotherembodiment.

FIG. 6 shows an embodiment of the invention comprising virtual use oflocation aware content to associate graffiti, chat room messages, blogs,etc., with a particular location, with an exemplary presence list for aModified Presence Information Data Format-Location Object (ModifiedPIDF-LO) for use in tying MIME type virtual content to a geospaciallocation, and for tagging the location with graphical and/or descriptiveinformation relating to the location, in accordance with the principlesof the present invention.

FIG. 7 shows a conventional LoCation Services (LCS) request.

FIG. 8 shows a conventional Presence Information Data Format-LocationObject (PDIF-LO) format document, as defined by the Internet EngineeringTask Force (IETF).

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention extends and modifies the otherwise conventionalformat of the Presence Information Data Format-Location Object (PIDF-LO)format as defined by the Internet Engineering Task Force (IETF).Conventional PIDF-LO document format tags actual people or places with ageospacial location. The otherwise conventional PIDF-LO format isextended or modified to associate a geospacial location to virtual data(e.g., to form graffiti, or Netfitti as referred to herein) on acomputer network such as the Internet, corporate Intranets, and/orcorporate Extranets.

In particular, a given location or location zone is associated withgraffiti type graphics and/or comments or blogging (referred to as“Netfitti” herein). Thus, instead of associating with a person, theinvention associates location with content, e.g., Internet XML content.

In accordance with the disclosed embodiments, content is referencedusing a location aware content modification to the otherwiseconventional PIDF-LO format as follows. A location is associated withInternet based XML reference content using a modified PIDF-LO formatusing the otherwise conventional <presence . . . > section listselements. Elements used include the “entity”, “src” and/or “name” fieldsare modified to associate a location with Internet based XML content.

As an example, the “entity=” element of the PIDF-LO format may bereferenced as, e.g., entity=“pres:http://ow.com/S.png”.

Similarly, the “name=” element may be referenced as, e.g.,name=“weather: hurricane season, century:1800, season:fall, year:1842”.

The “src=” element may be referenced as, e.g., http://ow.com/s.png.

Individuals and entities are referenced in the conventional PIDF-LOformat by a universal resource indicator (URI), e.g.,“pres:mike@samplecarrier.com”. As modified herein to associate locationto Internet based content, words are included within the content toindicate an active reference to the relevant content subject. Thesewords may be inserted, e.g., in the <meta name “keywords”> section of anHTML document.

Location may be associated to Internet based XML content using an XMLbased structure either (a) using Simple Object Access Protocol (SOAP);or (b) using Session Initiation Protocol (SIP).

Exemplary specific location aware (“Location”) content tags include,e.g., a specific location identified by latitude and longitude(lat/lon); or a specifically defined zone.

A location zone may be defined, e.g., using a coordinate based polygonsystem. A suitable coordinate based polygon is disclosed and describedin co-owned and co-pending U.S. patent application Ser. No. 11/442,254,filed May 30, 2006, entitled “Voice Over Internet Protocol (VoIP) E911Metro Street Address Guide (MSAG) Validation”; which claims priorityfrom 60/685,075, filed May 27, 2005, entitled “Voice Over InternetProtocol (VoIP) E911 Metro Street Address Guide (MSAG) Challenges”, byTimothy J. Lorello, the entirety of both of which are expresslyincorporated herein by reference.

A coordinate based polygon system defining location zone may have anassigned numbering system. For example, the assigned number “1.0.0.0”may be used to indicate a four (4) square kilometer (Km) area with anassigned centroid lat/lon; the assigned number “1.1.0.0” may be used toindicate a two (2) square Km area with an assigned centroid lat/lon; theassigned number “1.1.1.0” may be used to indicate a one (1) square Kmarea with an assigned centroid lat/lon; and the assigned number“1.1.1.1” may be used to indicate a one-half (0.5) square Km area withan assigned centroid lat/lon.

Location may be defined directionally, e.g., as “north”, “south”,“east”, “west”, etc.

In another embodiment, XML content (e.g., photos on the Internet) can beprovided with descriptive information using location aware content tagsincluded in the presence information of a PIDF-LO document. Exemplarylocation aware content tags include, e.g., “Time Reference”, “WeatherReference”, and/or “Descriptive Reference” tags.

Regarding various content types, several protocols allow the use of datarepresenting different ‘media’ such as text, images, audio, and video,and within such media different encoding styles, such as (in video)JPEG, GIF, IEF, and TIFF. The Multimedia Internet Message Extensions(MIME) protocol defines several initial types of multimedia dataobjects, and a procedure for registering additional types with theInternet Assigned Numbers Authority (IANA): text, images, audio andvideo.

FIG. 1 shows relevant elements associating MIME type content on theInternet to a geographic location while also correlating otherdescriptive indexing terms within a modified standards based XML basedPIDF-LO structure as defined by the Internet Engineering Task Force(IETF), for use with standardized Internet protocols such as IP, SIP andSOAP, in accordance with one embodiment.

In particular, FIG. 1 shows elements in a given network relevant toassociating location to XML content in an Internet network. Content 100on a relevant network server is associated with location by networkelements, including a user agent 101, an application server 102, acontent proxy 104, a presence server 105, a profile database 103, ageographic information server (GIS) server 106, a user plane server 107,a global positioning satellite (GPS) 108, and a menu of locations 109.

FIGS. 2 and 3 show message flow between the relevant elementsassociating MIME type content on the Internet to a geographic location,as shown in FIG. 1.

In particular, in step 1 of FIGS. 2 and 3, content 100 is sent to thecontent proxy 104 using an XML/SOAP interface. The content 100 may be,for the sake of example, http://otiswyres.com/images/sun.png”. Thetransaction uses an XML based Modified Presence Information DataFormat-Location Object (MPIDF-LO) as described herein.

In step 2, the content proxy 104 passes the universal resource locator(URL) of the content 100 to the presence server 105. The presence server105 establishes a record of the content 100 and all associated tags.

In step 3, the presence server 105 sends a lat/lon or polygon “Request”to the GIS server 106. The lat/lon relates to a location of the content100.

In step 4, the GIS server 106 determines the polygon ID associated withthe provided lat/lon of the content 100.

In step 5, the GIS server 106 returns back the determined polygon ID.

In step 6 a, the user starts up a main application on the user agent101, selects an instance to run, and (as shown in steps 6 b-6 d) theLocation type, and passes relevant logon information to the applicationserver 102.

In step 6 b, the assisted global positioning system “aGPS” and a userplane server 107 (e.g., a SUPL server with aGPS) in a carrier networkprovide location. Alternatively, as shown in step 6 c, a BLUETOOTH™ GPS108 may provide location. Another alternative, shown in step 6 d, allowsthe user to select a location from a menu of locations, e.g., “Paris”,“Camaria”, etc. 109.

In step 7, the application server 102 looks up the user profile for theapplication instance, and completes the logon process. Profile data ispassed from the profile database 103 back to the application server 102.

In step 8, the user agent 6 a receives location from the source (step 6b, 6 c or 6 d).

In step 9, the user agent 101 sends its location to the GIS server 106,e.g., “user ‘X’ indicates that ‘I am here’”.

In step 10, the GIS server 106 identifies the polygon within which theuser agent 101 is currently located.

In step 11 a, the GIS server 106 passes the identified polygon ID to theapplication server 102, e.g., “user ‘X’ is in this polygon at thisabsolute position”.

In step 11 b, the GIS server 106 returns the identified polygon ID andlat/lon of the polygon centroid to the user agent to the application onthe user agent 101.

In step 12, the application server 102 requests identification of whatcontent has presence in the identified polygon for this applicationinstance. For example, a list of content with presence in this polygonmay be provided, for this application instance, and within the relevantuser profile.

In step 13, the presence server 105 returns to the application server102 a list of content (or content tags) relevant to the user profile,this application instance, and this polygon ID, e.g., the URL of contentwith presence for this polygon [or content type tags only].

In step 14 a, the application server 102 uses the URL for each elementin the list of content and sends a URL request (e.g., hyper-texttransfer protocol (HTTP)) to the relevant content 100. Or, as shown instep 14 b, the application server 102 requests content type tags fromthe user agent 101. Or, as shown in step 14 c, the application server102 requests from the user agent 101 the identity or URL of content.

In step 15 a, the requested content is returned to the applicationserver 102, or the content URL from step 14 c is relayed from theapplication.

In step 15 b, the user agent 101 requests the content for each element,e.g., via Hyper Text Transfer Protocol (HTTP) and the URL of requestedcontent.

In step 16, the content is returned to the application on the user agent101 directly from the content source 100, or from the application server102.

In step 17, the application on the user agent 101 displays or otherwiseutilizes the received content.

FIG. 4 shows exemplary presence lists for a Modified PresenceInformation Data Format-Location Object (Modified PIDF-LO) document foruse in tying MIME type logical content to a geospacial location, and fortagging the content with descriptive information relating to thecontent, in accordance with another embodiment.

In particular, as shown in FIG. 4, an otherwise conventional PIDF-LOformat is modified to use the “entity=”, “name=”, and “src=” lists inthe presence section of a modified PIDF-LO format to identify XMLcontent. In this particular example, the XML content is identified as:

entity=”pres:http://otiswyres.com/images/SunfromPlane.png”src=http://otiswyres.com/images/SunfromPlane.png”and within the first tuple is:srsName=“http://www.opengis.net/gml/srs/epsg.xml#4326

Note also in FIG. 4 the addition of descriptive tags to XML content.Predefined tags in this example are “weather”, “century”, “season” and“year”.name=“weather:hurricane season, century: 1800, season: fall, year: 1842”

Thus, the location aware content defined by the “entity=” list in thepresence section of the MPIDF-LO document is further modified with adescription of hurricane season, 1800 century, fall season, and 1842.

FIG. 5 shows exemplary presence lists for a location awarecontent-Modified Presence Information Data Format-Location Object(Modified PIDF-LO) for use in tying MIME type logical content to ageospacial location, and for tagging the content with descriptiveinformation relating to the content, in accordance with yet anotherembodiment.

In particular, as shown in FIG. 5, an otherwise conventional PIDF-LOformat is modified to use the “entity=”, “name=”, and “src=” lists inthe presence section of a modified PIDF-LO format to identify XMLcontent. In this particular example, the XML content is identified as:

entity=&ltimg src=http://otiswyres.com/images/SunfromPlane.png name=”Sunfrom Plane”and within the first tuple is:srsName=“http://www.opengis.net/gml/srs/epsg.xml#4326”

Note also in FIG. 5 the addition of descriptive tags to XML content. Asin the example of FIG. 4, Predefined tags in the example of FIG. 5 are“weather”, “century”, “season” and “year”.

tag:weather=”hurricane” tag:century=”1800” tag:season=”fall”tag:year=”1842”

Thus, the location aware content defined by the “entity=” list in thepresence section of the MPIDF-LO document is further modified with adescription of hurricane, 1800 century, fall season, and 1842.

FIG. 6 shows an embodiment of the invention comprising virtual use oflocation aware content to associate graffiti, chat room messages, blogs,etc., with a particular location.

In particular, the embodiment discloses an exemplary presence list for aModified Presence Information Data Format-Location Object (ModifiedPIDF-LO) for use in tying MIME type virtual content to a geospaciallocation, and for tagging the location with graphical and/or descriptiveinformation relating to the location, in accordance with the principlesof the present invention.

In particular, as shown in FIG. 6, Location Aware Content refers tocontent that is (or was) geographically present at some point in time.In accordance with this aspect, the term Virtual Location Aware Contentrefers to content that is created to overlay geographically presentcontent.

For instance, an application can associate overlay images onto ageographic location. Netfitti is a grafitti like image that usesdescriptive reference tags (e.g., “virtual=”, and a geographic locationrepresentation (i.e., lat/lon). Virtual location aware content allows agraffiti graphics file, and then geo-tagging that electronic image to aspecific location (lat/lon).

Thus, the present invention associates virtual content with a location,i.e., associates virtual content to location, e.g., to display buildingswithin a ‘real’ location. In this way, virtual content such as agraffiti image can be displayed on the side of the building (as if itwas there in actuality).

The distinction between using PIDF-LO to associate a web page with alocation as described in the earlier embodiments, and using PIDF-LO toassociate virtual content with a location, is best explained by ageneral comparison of FIG. 6 (Virtual Location Aware Content as in thisembodiment) to FIG. 5 (Location Aware Content).

In particular, as seen in FIG. 5, the “entity=” parameter was filledwith a web page on the Internet. In that example, that web page wasassociated with a given location. In FIG. 6, the “entity=” parameter isfilled with an image to be overlayed on content associated with thelocation, as directed by the tag:virtual=“netffiti”. Thus, to indicatethat virtual content is to be associated with a location, the “entity=”parameter is used to indicate a graffiti file, e.g., “netfitti1.png”.

While the invention has been described with reference to the exemplaryembodiments thereof, those skilled in the art will be able to makevarious modifications to the described embodiments of the inventionwithout departing from the true spirit and scope of the invention.

What is claimed is:
 1. A method of associating a geospacial location tocontent on a network, comprising: identifying, at a physical networkserver, geospacial location information; identifying, at said physicalnetwork server, an Extensible Markup Language (XML) content identifieridentifying XML content; associating, at said physical network server,geospacial location information with said XML content via said XMLcontent identifier; and formulating, at said physical network server,Presence Information Data Format-Location Object (PIDF-LO) dataincluding said geospacial location information associated with said XMLcontent via said XML content identifier.
 2. The method of associating ageospacial location to content on a network according to claim 1,wherein: a filename of said XML content identifier is inserted in an“entity=” list in a <presence . . . > section of said modified PIDF-LOdata.
 3. The method of associating a geospacial location to content on anetwork according to claim 2, wherein: a filename of said XML contentidentifier is inserted in a “src=” list in a <presence . . . > sectionof said modified PIDF-LO data.
 4. The method of associating a geospaciallocation to content on a network according to claim 1, wherein: afilename of said XML content identifier is inserted in a “src=” list ina <presence . . . > section of said modified PIDF-LO data.
 5. The methodof associating a geospacial location to content on a network accordingto claim 1, wherein: said filename of said XML content identifier isinserted in a “name=” list in said <presence . . . > section of saidmodified PIDF-LO compliant data.
 6. The method of associating ageospacial location to content on a network according to claim 1,wherein: said geospacial location information identifies a specificzone.
 7. The method of associating a geospacial location to content on anetwork according to claim 6, wherein: said specific zone is definedusing a coordinate based polygon system.
 8. The method of associating ageospacial location to content on a network according to claim 7,wherein: said coordinate based polygon system is defined using anassigned numbering system.
 9. The method of associating a geospaciallocation to content on a network according to claim 1, wherein: saidgeospacial location information identifies a specificlatitude/longitude.
 10. The method of associating a geospacial locationto content on a network according to claim 1, wherein: said geospaciallocation information is defined directionally.
 11. The method ofassociating a geospacial location to content on a network according toclaim 1, wherein: said network is an Internet.
 12. The method ofassociating a geospacial location to content on a network according toclaim 1, wherein: said network is a corporate Intranet.
 13. The methodof associating a geospacial location to content on a network accordingto claim 1, wherein: said network is a corporate Extranet.
 14. Themethod of associating a geospacial location to content on a networkaccording to claim 1, wherein: said XML content comprises text.
 15. Themethod of associating a geospacial location to content on a networkaccording to claim 1, wherein: said XML content comprises at least oneimage.
 16. The method of associating a geospacial location to content ona network according to claim 1, wherein: said XML content comprisesaudio.
 17. The method of associating a geospacial location to content ona network according to claim 1, wherein: said XML content comprisesvideo.
 18. The method of associating a geospacial location to content ona network according to claim 1, wherein: said XML content is MultimediaInternet Message Extensions (MIME) type content.
 19. The method ofassociating a geospacial location to content on a network according toclaim 1, further comprising: tagging descriptive information relating tosaid XML content identifier in a <presence . . . > section of saidmodified PIDF-LO data.
 20. The method of associating a geospaciallocation to content on a network according to claim 19, wherein: saidtagged descriptive information is included in a <presence . . . >section of said modified PIDF-LO data.
 21. The method of associating ageospacial location to content on a network according to claim 19,wherein: said tagged descriptive information includes a “virtual=” tag.